This invention relates to a cover for the probe of an infrared radiation thermometer and, more particularly, to a cover which includes a film insert therein.
One of the types of thermometers in use today for recording body temperature is the infrared radiation (IR) thermometer. In order to determine body temperature, infrared thermometers use a hollow probe or speculum to establish a radiation pathway between a selected body surface into which the probe is inserted, such as the external ear canal, and a thermal radiation detecting element in the thermometer.
A disposable cover or sheath is normally removably secured over the tip of the probe to provide a clean, sanitary thermometer surface and also to keep the probe tip free of ear wax and hair.
Because the probe cover must be transparent to the infrared radiation being emitted through the tip of the probe, the cover typically incorporates a window in the tip thereof which is made of a material having a thickness less than the thickness of the material which forms the remainder of the cover.
In some of the probe covers, the material forming the infrared window is unitary with the material forming the rest of the cover while, in other covers, the material forming the window comprises a separate strip of film which is bonded or otherwise secured over the tip of the cover.
U.S. Pat. No. 5,088,834 discloses a probe cover where the infrared window and the body of the cover are of unitary construction and injection molded as one unitary piece with the material forming the window having a thickness which is less than the thickness of the material forming the body of the cover.
A disadvantage associated with unitary construction, however, is that current plastic molding apparatus and methods do not allow for the accurate and consistent molding of covers with windows and bodies having thicknesses in the required ranges.
U.S. Pat. No. 4,662,360 discloses a probe cover where the infrared window is made of a separate film of material bonded over the front of the tip of the cover. A disadvantage associated with this two-part probe cover however is that it requires the film comprising the window to be bonded to the cover immediately following the molding of the body to assure an adequate bond. Another disadvantage is that the film comprising the window creates a seam on the exterior of the cover which could be irritating to the ear during use. Yet a further disadvantage is the risk that the film, if not properly bonded, could separate from the cover while the thermometer is being used. Yet another disadvantage is that the material forming the window and the body respectively must preferably be made of the same material to maximize the strength of the thermal bond.
What is thus needed is a probe cover where the separate film of material forming the window is easily and effectively bonded to the interior of the probe cover.
The present temperature probe cover provides an infrared transparent window bonded to the interior surface of a hollow body of the probe cover. Particularly, the present cover for the temperature probe of a radiation detecting thermometer includes a hollow sheath or body which defines an interior surface, a proximal end opening for receiving the probe, a distal end opening in registry with the transparent end of the probe, and a separate transparent film insert which is secured to the interior surface of the sheath or body and occludes the distal end opening of the sheath to form the radiation transparent window. In one embodiment, the film insert comprises an elongate strip of film material which is adhesively secured to the interior surface of the sheath between the proximal and distal end openings respectively.
Also, in one embodiment, the probe cover includes an annular flange adjacent the proximal end opening thereof and opposed ends of the strip of film material are secured to the flange.
In another embodiment, the film insert is a campanulate insert which is secured to the interior surface of the sheath and occludes the sheath distal end opening.
The method for making the cover of the present invention includes the steps of providing the sheath and the film insert and then securing the film insert to the interior surface of the sheath in a relationship where the film insert covers the distal end opening of the sheath.
In one method embodiment where the film insert is an elongate strip of film material, the step of securing the strip of film material to the interior surface of the sheath includes the step of wrapping and securing the elongate strip of film material around the interior surface of the sheath in a relationship where the ends of the film material are generally diametrically opposed to each other and are secured to the interior surface adjacent the proximal end opening thereof.
Other advantages and features of the present invention which will be more readily apparent from the following detailed description of the preferred embodiment of the invention, the accompanying drawings, and the appended claims.